1. Field of the Invention
This invention relates generally to semiconductor fabrication, and more particularly, to a tool for use in the fabrication of semiconductor devices.
2. Discussion of the Related Art
End-of line (EOL) fabrication of semiconductor devices includes processing at mold, post mold cure, plating, and trim and form stations. A magazine holding a stack of strips including lead frames with die thereon is loaded onto the mold station. The strips are fed one at a time from the magazine into the mold station for processing, and are loaded one at a time from the station into another magazine after such processing. The loaded magazine is then moved to and placed in a cure oven at the post mold cure station. After curing, the magazine containing the strips is loaded onto the next (plating) station. The strips are fed one at a time from the magazine into the plating station for processing, and are loaded one at a time from the station into another magazine after such processing. This loaded magazine is transported to a trim and form station, where again the strips are fed one at a time from the magazine into the trim and form station for processing.
A typical magazine 20 for use in this environment is shown in FIG. 1. The magazine 20 includes a back portion 22, side portions 24, 26, front edges 28, 30 and a bottom support plate 32 on which a plurality of strips 34 is stacked. The magazine 20 as shown in FIG. 1 contains, for example, a stack of strips 34 (FIG. 2) each of which is made up of a lead frame 36 and a plurality of die (not shown) packaged in molding compound 38. As noted, the bottom portions of packages 38 of a strip 34 lie on and contact the top portions of the packages 38 of the strip 34 therebelow.
After, for example, post mold cure, which is undertaken at a very high temperature for an extended time, it will be readily understood that with the strips 34 stacked as shown in FIGS. 1 and 2, the packages 38, and thus the strips 34, may become attached to or stuck to each other. In this state, when the magazine 20 holding these strips 34 is installed at the next (plating) processing station, the mechanism for feeding strips 34 into that processing station may pick up two or more (stuck together) strips 34 at the same time, causing jamming of the processing station and undesirable process down time.
In attempting to deal with this problem, prior to installation of the magazine 20 at a processing station, an attempt can be made to separate the stuck-together strips 34 manually, i.e., using one's fingers. This is time-consuming and has proven to be ineffective, as some strips 34 may remain attached or stuck together. As an alternative, tweezers or other sharp objects have been used in an attempt to separate the strips 34, but it has been found that this method has great potential for causing strip damage.
Therefore, what is needed is a method/tool for separating strips that may have become attached together, to insure that a magazine loaded onto a processing station contains only separated or free strips which can be fed one at a time from the magazine into the processing station.